| Alldis, James, House | Torrington | Building | 1982 |
| American Legion Forest CCC Shelter | Barkhamsted | Building | 1986 |
| Anderson, Leroy, House | Woodbury | Building | 2012 |
| Bacon, Jabez, House | Woodbury | Building | 1971 |
| Baldwin, Amos, House | Norfolk | Building | 2016 |
| Barkhamsted Center Historic District | Barkhamsted | District | 1999 |
| Beardsley, Capt. Philo, House | Kent | Building | 1979 |
| Beaver Meadow Complex Prehistoric Archeological District | Barkhamsted | District | 1988 |
| Beckley Furnace | Canaan | Structure | 1978 |
| Bellamy, Joseph, House | Bethlehem | Building | 1982 |
| Benedict, Francis Jr., House | Norfolk | Building | 2002 |
| Bethlehem Green Historic District | Bethlehem | District | 1982 |
| Bissell, Henry B., House | Litchfield | Building | 1990 |
| Boardman's Bridge | New Milford | Structure | 1976 |
| Braman Camp | Norfolk | Building | 1982 |
| Bridge #2305 | Salisbury | Structure | 2007 |
| Bridge No. 560 | Cornwall | Structure | 2004 |
| Bridgewater Center Historic District | Bridgewater | District | 2000 |
| Brooks, Hervey, Pottery Shop and Kiln Site | Goshen | Site | 1993 |
| Bryan, Roderick, House | Watertown | Building | 2000 |
| Bull's Bridge | Kent | Structure | 1972 |
| Bull, Capt. William, Tavern | Litchfield | Building | 1983 |
| Burlington-Harmony Hill Roads Historic District | Harwinton | District | 1996 |
| Burrall-Belden House | Canaan | Building | 2018 |
| Calhoun-Ives Historic District | Washington | District | 1995 |
| Camp, Moses, House | Winsted | Building | 1984 |
| Canaan Pine Grove Association Camp Meeting | Canaan | District | 2021 |
| Canaan Village Historic District | North Canaan | District | 1990 |
| Catlin, J. Howard, House | Litchfield | Building | 1993 |
| Chapin, Philip, House | New Hartford | Building | 1977 |
| Childs, Starling, Camp | Norfolk | Building | 1982 |
| Coffing, John C., House | Salisbury | Building | 1990 |
| Colebrook Center Historic District | Colebrook | District | 1991 |
| Colebrook Store | Colebrook | Building | 1976 |
| Cornwall Bridge Railroad Station | Cornwall | Building | 1972 |
| Cream Hill Agricultural School | West Cornwall | Building | 1976 |
| Cream Hill Shelter | Sharon | Building | 1986 |
| Downtown Torrington Historic District | Torrington | District | 1988 |
| East Plymouth Historic District | Plymouth | District | 1985 |
| Esperanza | New Hartford | Building | 2002 |
| Ezekial Beardsley-David Hare House and Studio | Roxbury | Building | 2025 |
| Falls Village District | Canaan | District | 1979 |
| Farnum House | Norfolk | Building | 1982 |
| Flanders Historic District | Kent | District | 1979 |
| Forbes, Samuel, Homestead | East Canaan | Building | 1992 |
| Foster, Stephen and Helen, House | Cornwall | Building | 2017 |
| Fyler-Hotchkiss Estate | Torrington | Building | 1987 |
| Gay, Ebenezer, House | Sharon | Building | 1979 |
| Gilbert Clock Factory | Winchester | Building | 1984 |
| Gillette's Grist Mill | Torrington | Building | 1977 |
| Glebe House | Woodbury | Building | 1971 |
| Goshen Historic District | Goshen | District | 1982 |
| Gould House | Norfolk | Building | 1982 |
| Gov. Smith Homestead | Sharon | Building | 1982 |
| Halpine, J. S., Tobacco Warehouse | New Milford | Building | 1982 |
| Harry O. Erikson Pavilion Hall | Washington | Building | 2022 |
| Haystack Mountain Tower | Norfolk | Structure | 1993 |
| Hillside | Norfolk | Building | 1982 |
| Hine-Buckingham Farms | New Milford | Building | 2004 |
| Holabird House | Canaan | Building | 1982 |
| Hollister, Homestead, The | Washington | Building | 2010 |
| Hose and Hook and Ladder Truck Building | Thomaston | Building | 1982 |
| Hotchkissville Historic District | Woodbury | District | 1996 |
| Housatonic Railroad Station | New Milford | Building | 1984 |
| Kent Iron Furnace | Kent | Structure | 1977 |
| Lakeville Historic District | Salisbury | District | 1996 |
| Lakeville Manor | Lakeville | Building | 2014 |
| Lawrence, Isaac, House | Canaan | Building | 1983 |
| Lime Rock Historic District | Salisbury | District | 1984 |
| Lime Rock Park Race Track | Salisbury | District | 2009 |
| Litchfield Historic District NHL | Litchfield | District | 1968 |
| Litchfield Historic District | Litchfield | District | 1978 |
| Litchfield-South Roads Historic District | Harwinton | District | 1996 |
| Lover's Leap Bridge | New Milford | Structure | 1976 |
| Low House | Norfolk | Building | 1984 |
| Martin, Caleb, House | Bethlehem | Building | 1996 |
| Mead Camp | Norfolk | Building | 1982 |
| Merritt Beach & Son Building | New Milford | Building | 1992 |
| Merryall Union Evangelical Society Chapel | New Milford | Building | 1986 |
| Merwinsville Hotel | Gaylordsville | Building | 1977 |
| Migeon Avenue Historic District | Torrington | District | 2002 |
| Milton Center Historic District | Milton | District | 1986 |
| Minortown Road Bridge | Woodbury | Structure | 2001 |
| Moore Jr., William, House | Barkhamsted | Building | 1999 |
| Moseley House-Farm | Norfolk | Building | 1984 |
| Moss Hill | Norfolk | Building | 1982 |
| Mount Riga Ironworks Site | Salisbury | Site | 1994 |
| Mount Tom Tower | Woodville | Structure | 1993 |
| Mulville House | Norfolk | Building | 1984 |
| Music Mountain | Canaan | Building | 1987 |
| New Milford Center Historic District | New Milford | District | 1986 |
| New Preston Hill Historic District | Washington | District | 1985 |
| Noble House | Norfolk | Building | 1984 |
| Noble, John Glover, House | New Milford | Building | 1977 |
| Norfolk Country Club House | Norfolk | Building | 1982 |
| Norfolk Downs Shelter | Norfolk | Building | 1984 |
| Norfolk Historic District | Norfolk | District | 1979 |
| Northfield Knife Company Site | Litchfield | Site | 1997 |
| Old Riverton Inn | Barkhamsted | Building | 1992 |
| Pardee, James, House | Sharon | Building | 2003 |
| Paugnut Forest Administration Building | Torrington | Building | 1986 |
| Peoples Forest Museum | Barkhamsted | Building | 1986 |
| Phelps Farms Historic District | Colebrook | District | 1983 |
| Phelps, Arah, Inn | North Colebrook | Building | 1971 |
| Pine Meadow Historic District | New Hartford | District | 1996 |
| Plymouth Center Historic District | Plymouth | District | 1999 |
| Plymouth Center Historic District (Boundary Increase) | Plymouth | Building | 2000 |
| Rectory and Church of the Immaculate Conception | Norfolk | Building | 1982 |
| Red Mountain Shelter | Cornwall | Building | 1986 |
| Reeve, Tapping, House and Law School NHL | Litchfield | Building | 1966 |
| Reynolds Bridge | Thomaston | Structure | 2004 |
| Riverton Historic District | Riverton | District | 2007 |
| Rock Hall | Colebrook | Building | 2010 |
| Rockwell House | Norfolk | Building | 1982 |
| Rockwell, Solomon, House | Winsted | Building | 1977 |
| Roxbury Center | Roxbury | District | 1983 |
| Roxbury Iron Mine and Furnace Complex | Roxbury | Site | 1979 |
| Rumsey Hall | Cornwall | Building | 1990 |
| Rye House | Litchfield | District | 2000 |
| Salisbury Center Historic District | Salisbury | District | 1997 |
| Sanford, Frederick S., House | Bridgewater | Building | 1989 |
| Schoverling, Carl F., Tobacco Warehouse | New Milford | Building | 1982 |
| Scoville Memorial Library | Salisbury | Building | 1982 |
| Scoville Powerhouse | Salisbury | Building | 1984 |
| Sedgwick, Maj. Gen. John, House | Cornwall | Building | 1992 |
| Sharon Historic District | Sharon | District | 1993 |
| Sharon Valley Historic District | Sharon | District | 1982 |
| Shepard, John, House | Norfolk | Building | 1982 |
| Sherman, David, House | Woodbury | Building | 2002 |
| Skee's Diner | Torrington | Building | 2002 |
| Skilton Road Bridge | Watertown | Structure | 1991 |
| Skinner, Jason, House | Harwinton | Building | 1985 |
| South Canaan Congregational Church | Canaan | Building | 1983 |
| South School | Torrington | Building | 1986 |
| Sports Building | Norfolk | Building | 1984 |
| St. Andrew's Episcopal Church | Washington | Building | 1994 |
| Steward's House, Foreign Mission School NHL | Cornwall | Building | 2016 |
| Stoeckel, Robbins, House | Norfolk | Building | 1982 |
| Sun Terrace | New Hartford | Building | 1978 |
| Sunny Ridge Historic District | Washington | District | 1995 |
| Tamarack Lodge Bungalow | Norfolk | Building | 1977 |
| Terryville Waterwheel | Plymouth | Structure | 2002 |
| Thomaston Opera House | Thomaston | Building | 1972 |
| Thumb, Tom, House | Norfolk | Building | 1984 |
| Topsmead | Litchfield | Building | 1993 |
| Torringford Street Historic District | Torrington | District | 1991 |
| Torrington Fire Department Headquarters | Torrington | Building | 1987 |
| Town Hall and District School No. 6 | Morris | Building | 1987 |
| Trinity Church | Milton | Building | 1976 |
| Trinity Church | Thomaston | Building | 1984 |
| Union Church/St. Paul's Church | Riverton | Building | 1985 |
| Union Depot | North Canaan | Building | 1972 |
| United Bank Building | New Milford | Building | 1982 |
| Villa Friuli | Torrington | Building | 1991 |
| Warner Theatre | Torrington | Building | 1984 |
| Warren Congregational Church | Warren | Building | 1991 |
| Warrenton Woolen Mill | Torrington | Building | 1987 |
| Washington Green Historic District | Washington | District | 1995 |
| Water Street Historic District | Torrington | District | 2003 |
| Watertown Center Historic District | Watertown | District | 2001 |
| Welch, David, House | Milton | Building | 1984 |
| West Cornwall Bridge | West Cornwall | Structure | 1975 |
| West End Commercial District | Winsted | Building | 1990 |
| West Goshen Historic District | Goshen | District | 1987 |
| Wildman, E. A., & Co. Tobacco Warehouse | New Milford | Building | 1988 |
| Winchester Soldiers' Monument | Winchester | Structure | 1984 |
| Winsted Green Historic District | Winsted | District | 1977 |
| Winsted Green National Register Historic District (Boundary Increase) | Winsted | District | 1982 |
| Winsted Hosiery Mill | Winsted | Building | 1985 |
| Winsted Water Works | Winchester | District | 2020 |
| Wolcott, Oliver, House NHL | Litchfield | Building | 1971 |
| Woodbury Historic District No. 1 | Woodbury | District | 1971 |
| Woodbury Historic District No. 2 | Woodbury | District | 1972 |
| World War I Memorial | Norfolk | Object | 1984 |